A benign, slow-growing tumor type, acoustic neuromas affect the seventh and eighth cranial nerves in a part of the brain known as the cerebellar-pontine angle, or CPA. The eighth cranial nerve has two parts – the cochlear nerve that transmits sound between the inner ear and the brainstem, and the vestibular nerve that helps provide balance. Acoustic neuromas most commonly arise from schwann cells, which produce insulation for the vestibular nerve. Therefore, these tumors are often called vestibular schwannomas.

CyberKnife® precisely aims radiation beams at the AVM from multiple angles. Over time, the radiation causes the AVM blood vessels to narrow and eventually close off, eliminating the risk of hemorrhage or stroke. The primary advantage over surgical removal is that radiosurgery is not invasive, does not require anesthesia or a hospital stay and doesn’t carry the risks of open surgery. Moreover, some AVMs are located in areas of the brain that cannot be treated with conventional surgery. In those cases, radiosurgery may be the only feasible treatment option.

CyberKnife differs from other radiosurgery systems in that it doesn’t require a rigid metal frame screwed to the patient’s skull for targeting tumors and immobilizing patients. The CyberKnife achieves highly accurate targeting with computer imaging that continuously updates the tumor location and, therefore, eliminates the need for a metal frame.

CyberKnife robotic stereotactic radiosurgery (SRS) painlessly delivers precise beams of high-dose radiation to brain tumors and lesions, without incisions, hospitalization, or long recovery time. CyberKnife SRS is a non-invasive alternative to brain cancer surgery and can be used for brain tumors that are considered inoperable because of their location in the head, for those patients who cannot undergo brain cancer surgery due to their poor medical condition, or who refuse surgery. The CyberKnife System also can treat benign, or non-cancerous, tumors and other conditions, such as trigeminal neuralgia and arteriovenous malformations (AVMs).

Radiosurgery for kidney tumors is noninvasive, and typically carries less risk of complications than conventional surgery. For patients who refuse surgery or have medically inoperable kidney tumors, radiosurgery can be an effective treatment option. CyberKnife, which delivers high-dose radiation over one to five treatments, can be particularly effective for treatment of small kidney tumors. CyberKnife has the ability to compensate for normal patient movements, precisely targeting the tumor during the entire procedure and minimizing damage to surrounding healthy tissue. This is important when treating kidney tumors, which can shift during treatment due to regular patient movements such as breathing.

CyberKnife’s ability to treat tumors with precisely focused radiation offers an important advantage for liver cancer patients. Accurate to within less than a millimeter, radiosurgery has minimal effect on surrounding health tissue. This level of accuracy enables doctors to target liver tumors with high-dose radiation, which significantly reduces the number of treatments needed – usually between three and five over several days compared to 30-40 over several weeks required for radiotherapy systems. Radiosurgery has other benefits as well, namely its ability to track tumors in real time. That means patients breathe normally during each treatment session, since the radiation beam adjusts automatically to the tumor location.

CyberKnife Robotic Radiosurgery painlessly delivers precise beams of radiation to tumors and lesions, without requiring incisions, hospitalization, or long recovery time. It can serve as an effective lung cancer treatment and is an especially good option for patients with early stage lung cancer, complex tumors or patients who prefer a non-invasive way to treat their cancer.

Metastatic tumors occur when cancer cells from the primary cancer spread to other areas of the body. The most common areas cancer cells spread to are the brain, lungs, liver and bones. When cancer spreads to another area, it has the same name and the same type as the original cancer. For example, renal cell cancer that has spread to the lung is called metastatic renal cell cancer, not lung cancer.

The CyberKnife robotic radiosurgery system is a widely used form of nonsurgical prostate stereotactic body radiation therapy (SBRT). The American Society for Radiation Oncology (ASTRO) believes that enough clinical evidence exists so that SBRT should be considered an appropriate alternative for select patients with low- to intermediate-risk prostate cancer.

CyberKnife is capable of high-dose radiation for tumors or lesions in especially sensitive areas of the brain and is the only radiosurgery system that doesn’t need an invasive head frame. Radiosurgery with CyberKnife safely delivers high-dose radiation while minimizing exposure to healthy tissue. Ocular and orbital tumors can be difficult to treat due to their close proximity to important structures in the brain, and CyberKnife provides an effective treatment option for these tumors due to the precise nature of the radiation beams it delivers. Ocular and orbital tumors can greatly affect a patient’s quality of life, and radiosurgery with CyberKnife offers a treatment option that can preserve a patient’s vision.

Prior to treatment, doctors implant between three to five small metal markers known as fiducials in or near the tumor that enable the CyberKnife to pinpoint the tumor location throughout treatment. Implanting the markers is an outpatient procedure that takes about an hour. About a week later, patients are fitted with a custom body mold made of soft material that they lie on during treatments. The fitting process is painless. Patients then undergo a CT scan that assists in developing a customized treatment plan.

Spine cancer is an abnormal growth of cells in or around the spinal cord resulting in a tumor. If the abnormal cells originated from cells in the tissues of the spine, this is a Primary Spine Tumor. Primary tumors in the spine are relatively rare and are either benign (non-cancerous) or malignant (cancerous).

Benign Spine Tumors include:

Meningiomas

Neurofibromas

Schwannoma

Malignant Spine Tumors include:

Astrocytomas

Ependymosas

If the abnormal cells originated in another part of the body, as in cancer originating in the lung, breast, colon or skin and were carried to the spine by the blood or other bodily fluid, growing into a tumor, then it is considered a Metastatic Spine Tumor. Both primary and metastatic spine tumors are very serious because they can compress the spinal cord and/or destroy the bone and surrounding tissue in the spine. These tumors cause patients to experience pain, gait and posture problems, and other neurological issues.

In the treatment of trigeminal neuralgia (TN), pain management with medication is traditionally the first line of defense. While this approach can reduce the effects of the disorder, some patients may require or request additional treatment due to advanced pain or a desire to avoid side effects of current medication. In these cases, the patient may be a candidate for CyberKnife treatment.

San Francisco CyberKnife is a service of and located at Saint Francis Memorial Hospital.

This site does not provide medical advice. The content is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition.